IkiWiki/Plugin/teximg.pm

   1 #!/usr/bin/perl
   2 # Licensed under GPL v2 or greater
   3 # (c) 2007 Patrick Winnertz <patrick.winnertz@skolelinux.org>
   4
   5 package IkiWiki::Plugin::teximg;
   6 use warnings;
   7 use strict;
   8 use Digest::MD5 qw(md5_hex);
   9 use File::Temp qw(tempdir);
  10 use HTML::Entities;
  11 use Encode;
  12 use IkiWiki 3.00;
  13
  14 my $default_prefix = <<EOPREFIX;
  15 \\documentclass{article}
  16 \\usepackage[utf8]{inputenc}
  17 \\usepackage{amsmath}
  18 \\usepackage{amsfonts}
  19 \\usepackage{amssymb}
  20 \\pagestyle{empty}
  21 \\begin{document}
  22 EOPREFIX
  23
  24 my $default_postfix = '\\end{document}';
  25
  26 sub import {
  27         hook(type => "getsetup", id => "teximg", call => \&getsetup);
  28         hook(type => "preprocess", id => "teximg", call => \&preprocess);
  29 }
  30
  31 sub getsetup () {
  32         return
  33                 plugin => {
  34                         safe => 1,
  35                         rebuild => undef,
  36                         section => "widget",
  37                 },
  38                 teximg_dvipng => {
  39                         type => "boolean",
  40                         description => "Should teximg use dvipng to render, or dvips and convert?",
  41                         safe => 0,
  42                         rebuild => undef,
  43                 },
  44                 teximg_prefix => {
  45                         type => "string",
  46                         example => $default_prefix,
  47                         description => "LaTeX prefix for teximg plugin",
  48                         safe => 0, # Not sure how secure LaTeX is...
  49                         rebuild => 1,
  50                 },
  51                 teximg_postfix => {
  52                         type => "string",
  53                         example => $default_postfix,
  54                         description => "LaTeX postfix for teximg plugin",
  55                         safe => 0, # Not sure how secure LaTeX is...
  56                         rebuild => 1,
  57                 },
  58 }
  59
  60 sub preprocess (@) {
  61         my %params = @_;
  62
  63         my $height = $params{height};
  64         if (! defined $height || ! length $height) {
  65                 $height = 12;
  66         }
  67         else {
  68                 $height =~ s#(\d+)#$1#;
  69         }
  70
  71         my $code = $params{code};
  72         if (! defined $code && ! length $code) {
  73                 error gettext("missing tex code");
  74         }
  75         return create($code, check_height($height), \%params);
  76 }
  77
  78 sub check_height ($) {
  79         # Since latex doesn't support unlimited scaling this function
  80         # returns the closest supported size.
  81         my $height =shift;
  82
  83         my @allowed=(8,9,10,11,12,14,17,20);
  84
  85         my $ret;
  86         my $fit;
  87         foreach my $val (@allowed) {
  88                 my $f = abs($val - $height);
  89                 if (! defined($fit) || $f < $fit ) {
  90                         $ret=$val;
  91                         $fit=$f;
  92                 }
  93         }
  94         return $ret;
  95 }
  96
  97 sub create ($$$) {
  98         # This function calls the image generating function and returns
  99         # the <img .. /> for the generated image.
 100         my $code = shift;
 101         my $height = shift;
 102         my $params = shift;
 103
 104         if (! defined($height) and not length($height) ) {
 105                 $height = 12;
 106         }
 107
 108         my $digest = md5_hex(Encode::encode_utf8($code), $height);
 109
 110         my $imglink= $params->{page} . "/$digest.png";
 111         my $imglog =  $params->{page} .  "/$digest.log";
 112         will_render($params->{page}, $imglink);
 113         will_render($params->{page}, $imglog);
 114
 115         my $imgurl=urlto($imglink, $params->{destpage});
 116         my $logurl=urlto($imglog, $params->{destpage});
 117
 118         if (-e "$config{destdir}/$imglink" ||
 119             gen_image($code, $height, $digest, $params->{page})) {
 120                 return qq{<img src="$imgurl" alt="}
 121                         .(exists $params->{alt} ? $params->{alt} : encode_entities($code))
 122                         .qq{" class="teximg" />};
 123         }
 124         else {
 125                 error qq{<a href="$logurl">}.gettext("failed to generate image from code")."</a>";
 126         }
 127 }
 128
 129 sub gen_image ($$$$) {
 130         # Actually creates the image.
 131         my $code = shift;
 132         my $height = shift;
 133         my $digest = shift;
 134         my $imagedir = shift;
 135
 136         if (!defined $config{teximg_prefix}) {
 137                 $config{teximg_prefix} = $default_prefix;
 138         }
 139         if (!defined $config{teximg_postfix}) {
 140                 $config{teximg_postfix} = $default_postfix;
 141         }
 142         if (!defined $config{teximg_dvipng}) {
 143                 $config{teximg_dvipng} = length `which dvipng 2>/dev/null`;
 144         }
 145
 146         my $tex = $config{teximg_prefix};
 147         $tex .= '\['.$code.'\]';
 148         $tex .= $config{teximg_postfix};
 149         $tex =~ s!\\documentclass{article}!\\documentclass[${height}pt]{article}!g;
 150         $tex =~ s!\\documentclass{scrartcl}!\\documentclass[${height}pt]{scrartcl}!g;
 151
 152         my $tmp = eval { create_tmp_dir($digest) };
 153         if (! $@ &&
 154             writefile("$digest.tex", $tmp, $tex) &&
 155             system("cd $tmp; shell_escape=f openout_any=p openin_any=p latex --interaction=nonstopmode $digest.tex < /dev/null > /dev/null") == 0 &&
 156             # ensure destination directory exists
 157             writefile("$imagedir/$digest.png", $config{destdir}, "") &&
 158             (($config{teximg_dvipng} &&
 159                 system("dvipng -D 120 -bg Transparent -T tight -o $config{destdir}/$imagedir/$digest.png $tmp/$digest.dvi > $tmp/$digest.log") == 0
 160             ) || (!$config{teximg_dvipng} &&
 161                 system("dvips -E $tmp/$digest.dvi -o $tmp/$digest.ps 2> $tmp/$digest.log") == 0 &&
 162                 system("convert -density 120  -trim -transparent \"#FFFFFF\" $tmp/$digest.ps $config{destdir}/$imagedir/$digest.png > $tmp/$digest.log") == 0
 163             ))) {
 164                 return 1;
 165         }
 166         else {
 167                 # store failure log
 168                 my $log="";
 169                 {
 170                         if (open(my $f, '<', "$tmp/$digest.log")) {
 171                                 local $/=undef;
 172                                 $log = <$f>;
 173                                 close($f);
 174                         }
 175                 }
 176                 writefile("$digest.log", "$config{destdir}/$imagedir", $log);
 177
 178                 return 0;
 179         }
 180 }
 181
 182 sub create_tmp_dir ($) {
 183         # Create a temp directory, it will be removed when ikiwiki exits.
 184         my $base = shift;
 185
 186         my $template = $base.".XXXXXXXXXX";
 187         my $tmpdir = tempdir($template, TMPDIR => 1, CLEANUP => 1);
 188         return $tmpdir;
 189 }
 190
 191 1